As is well known, there are several microbial species found in soil and water that are capable of assimilating petroleum hydrocarbons. Unfortunately, the rate of microbial assimilation of petroleum hydrocarbons is relatively slow. It is necessary, therefore, to stimulate the microbial assimilation if bioremediation is to be utilized in removing such pollutants from soils and water.
In general, the rate and extent of microbial utilization of petroleum hydrocarbons is limited by the concentration of microbial nutrients and microflora available at the hydrocarbon-water interface. Thus, microbial nutrients, especially nitrogen-containing nutrients like urea, have been added to contaminated soil or water as a method for enhancing the biodegradation of the petroleum contaminants. Because these nitrogen-containing microbial nutrients are generally water soluble and because the petroleum hydrocarbons are hydrophobic, the nutrients are generally delivered in an aqueous solution, along with a surfactant which aids in delivering the microbial nutrients to the hydrocarbon-water interface. Although this approach is useful, there remains a need for increasing the microflora available for hydrocarbon assimilation in order to further enhance the bioremediation process.
Accordingly, it is an object of the present invention to provide an improved composition and method for stimulating the propagation of naturally occurring hydrocarbon assimilating microflora to enhance the bioremediation of hydrocarbon contaminated water and soils.